race condittion fnDeleteRow

gistfile1.js

    $(document).ready( function () {
      var table;
      table = $('#urls_table').dataTable( {
        "bProcessing": true,
        "sAjaxSource": "/test.pl/url/all/",
        "sDom": 'T<"clear">lfrtip',
        "sPaginationType": "full_numbers",
        "oTableTools": {
          "sRowSelect": "multi",
          "aButtons": [
            "select_all",
            "select_none",
            {
              "sExtends": "select_none",
              "sButtonText": "Delete",
              "fnClick": function () {
                var tableTools = TableTools.fnGetInstance( 'urls_table' );
                var rows = tableTools.fnGetSelected();
                for(var i = rows.length-1; i >= 0 ; i--) {
                //for(var i = 0; i < rows.length; i++) {
                  var row = rows[i];
                  var pkey = row.getAttribute('id');
                  $.ajax({
                    url: "/test.pl/url/delete/",
                    async: false,                           // it doesnt work when set to true !
                    type: "POST",
                    data: {"pkey" : pkey},
                    statusCode: {
                      204: function () {
                        table.fnDeleteRow( row );
                      },
                      404: function () { alert("Cannot delete URL with id: " + pkey); },
                    }
                  });
                }
              }
            }
          ]
        },
       } );
    } );